People were outraged when the official account of the Whatley Manor Hotel near near Malmesbury retweeted a comment made by Tomi Lahren, who works for right-wing US TV channel Fox.
Her Tweet said: "She (Greta) cries crocodile tears and we are supposed to jump? What about the hundreds of thousands who will lose their jobs, their industries, their identities, their means to provide for their families, and their entire way of life if the measures this girl demanded were put into place?"
The Whatley Manor Twitter account then blocked some people who criticised them for retweeting the message.
But this morning Whatley put a message on its account saying: "The Whatley Manor Twitter account has been hacked today and various actions including re-tweets were made without our knowledge.
"Our Twitter account is only used for good news stories about our hotel, team and the hospitality industry in general."
Sixteen-year-old Greta Thunberg achieved world fame by calling for action on climate change. Earlier this week, she gave an emotional speech to world leaders at a meeting of the UN in New York.
She was later mocked by US president Donald Trump.